Method of treating ore.



PATENTBD .TUNE 23, 1908. J. T. JONES.

N0. 891,704. PATENTBD JUNE 23, 1908. J. T. JONES.

METHOD OP TREAT-ING ORE.

APPLIGATION FILED APR.11,190B.

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UNITED STATES PATENT OEEIOE.

llOHN T. JONES, OF IRONv MOUNTAIN, MICHIGAN, ASSIGNOR OF ONE-HALF TO GEORGE A. ST, CLAIR, OF DULUTH, MINNESOTA.

METHOD OF TREATING ORE.

Specification of Letters Patent.

Application med 1mi 11, 190s. sen'al Nc. 426,454.

tion consists, briefly stated, in first subject-t ing the Ore to, more Ior less nearly complete, reduction in a deoxidizing atmosphere at a temperature too low to melt either the slag making constituents or metallic iron, then vsubjecting the resultant spon'y mass to a higher tem1 erature which render fluid the slag ma g constituents but not the metallic iron, and then rolling and squeezing the mass to work out the slag.

In carrying out of my method on a cominercial scale it is necessary to employ a furnace, or a plurality of furnaces and, `for the purpose of illustration merely, I show in the accompanying drawings furnace structures in which'the steps of my method may be carried out. l

Referring to the drawings- Figure iis a view, partly sectional and partly in sid elevation, of a furnace vstructure adapted for carrying out ofthe first steps of my improved method; and Fig. 2 a sectional view of a ball-v ing furnace of common construction for carrying out further steps of my method.

A furnace 3 for the production of reducing gas is provided with a as-outlet flue 4. Fuel, as bituminous coa is fed thereto through a bell-valve 5, and air to support combustion is forced in through the twyer v6. The unvolatili'zed products of the fuel may be drawn through the opening 7.v A- n inclined rotary cylinder 8 abuts gas' tight against the mouth .of the flue 4 and is supported upon rollers 9 in a common manner. The cylinder 8 in practice, may be, say, one hundred or more feet in length. 10 is a second cylinder forming, in effect, a continuation ofthe cylinder 8 and similarly mounted to rotate therewith. The upper Open end of the cylinder 10 enters the lower part of a stationary ore-feeding hopper 11, the joint between them being as-tight. Air-supplying pi es 12 enter'the ower end-portion of the cy inder 10 and lead thereto from a common air-supply pipe 13. On the upper end-portion of the cylinder 8 is a hopper 14 provided with a valve 15, the hopper communicating with a pipe 16 which terminates at about the axial center ofthe cylinder. Below the open lower end of the cylinder 8v is a pit 17 into which cars 18 may be' run to receive the material discharged from the cylinder 8.

`The reducing gases generated in the furnace 3 pass through the flue 4 into the lower end of the cylinder 8, and, when they reach the cylinder 10, theyare mixed with air from the pipes 12, giving to the gases an excess of oxygen. All the gases escape through the hopper 11. The cylinders have means, not

shown, for rotating them slowly, andthe ore fed through the hopper 11 descends slowly to the lower end of the cylinder 8. In its passage through the cylinder 10, the ore is subjected to an oxidizing atmosphere which tends to drive off sulfur and heat the ore to a hightemperature. Whiledescending through the cylinder 8, the oie is subjected to a reducing atmosphere which is maintained at a temperature sufiiciently high to reduce the desired percentage of the iron oxids to metal, without,

owever, rendering either the metallic iron or slag producing constituents of the ore Huid.

The temperature of the gases passing through the cylinders is regulated within reasonable limits to produce 'the results I wish to obtain. Occasionally, as desired, I

feed a more or less limited quantity of preferably bituminous coal into the u er end of the cylinder 8 through the valve opper 14. As the Ore passes through the upperend-portion of the cylinder 8, it is subjected to a reducing temperature which does not, however, reach that necessary to bind phosphorus to the metal. It is, however, hlgh enough to free the volatiles from the hydro-carbon fuel fed through the hopper 14, and these volatiles mixed with the reducing gases from the furnace 3 tend to combine with any phosphoric acid in the Ore and carry it Off. Thus the'ore as it descends through the c linder 8 is not only reduced, but largely, at east, dephosphorized.

As the iron oxids are reduced to the metallic state, the reduced metal particles tend to agglomerate together and form structures Patented .Tune 23, 1908.

of honeycomb form, while the other constite lin volume suliicient to deteriorate the reducing gases entering the cylinder from the flue 4. When a car 18 is illed with reduced ore, its contents may be covered with coal-dust or the like, to exclude the atmosphere and prevent reoxidation of the ore.

To carryout the next step of my method, the rotary balling furnace 19 shown in Fig. 2 may be employed. This furnace is of common construction having a body-portion 20 which is mounted to rotate. portion .is a chamber 21 having a charging opening 22 at one side closed by a normally stationary door 23. The door is mounted upon a stationary support to slide into and out of its closing position and contains a tap opening 24 closed by a swinging valve 25. In a stationary frame at the o posite side ofthe body-portion 20 is an in et passage 26 to which extends a hydrocarbon burner 27. Below the passage 26 is an outlet passage for gases 28. The passages 26 and 28 register with a passage 29 to the chamber 21. In practice, the door 23 being opened, the contents of a car 18 are charged through the opening 22 into the chamber 21 when the door is again closed andthe reduced spongy -masssubjected to heat from the hydro-carbon burner 27. `slowly rotated, the mass is rol ed over and As the bodyortion 20 is over, the temperature to which it is subjected being suflicient to render the slag mak mg constituents fluid and to render the etal viscous, then asty. The weight of the metal forming tlie mass tends to squeeze out the fluid slag as it forms, and when the slag In the bodybath rises above the outlet 24, it overflows, opens the valve 25 and escapes.

It is to be understood that if the ore is not primarily self-fluxing, suitable fluxing material must be mixed therewith, and it is desirable that the slag roducing constituents of the ore or mass shall much below that required for meltingmetallic iron, say under 220()Ov F. The temperature of the chamber 21 during this balling operation is maintained well above that required for rendering the slag making constituents fluid but below that necessary to render the metallic iron constituent (of the mass more than pasty. lVhen the mass has been thus squeezed and rolled until most of the slag is worked out, the resultant lball. or muck bar is removed from the chamber 21 for"further treatment as by rollin under a welding heat, to further eliminate s ag il necs essary.

I wish it t0 be understood that I do not limit my invention to the employment of the particular furnaces shown and described.

What I claim as new, and desire to secure by Letters Patent, is

`The method of treating iron ore, which consists in first subjecting the ore under deoxidizing conditions to a tem erature that will reduce tiron oxids to meta without rendering the slag making constituents fluid, then subjecting the reduced ore under a higher tem erature which will render fluid the slag ma ing constituents but not the metallic iron to a rolling and squeezing opera# tion to work out the slag.

JOHN T. JONES.

In presence of- L. G. KIRKLAND, R. A. SCHAEFER.

melt at a temperature- 

